فصلنامه جغرافیای طبیعی
پیاپی 28 (تابستان 1394)

Assessment of reference evapotranspiration to estimate aqueous Plants’ needs, to manage aquatic and drainage plans and irrigation timing of plants are some necessities of agriculture section. So in this research to find the best model for estimation of reference evaporation and transpiration for catchment basin of East and South Eastern of the Country, relying on clustering method and considering data made by 66 weather stations, reference evaporation and transpiration made by evaporation basin was assessed and compared to evaporation and transpiration measures of 8 equations based on statistical parameters: r, t, d, MAE, MBE, NRMSE. Based on the results, considering the different time dimensions, the methods Hargreaves - Samani, Blaney – Criddle – FAO 24, Turk and Priestley – Taylor, have the best conformity with reference evapotranspiration values resulted by evaporation pan. Also the results of research show that in seasonal scale, summer had the minimum and winter had the maximum estimation error of ETO .On the other hand, monthly scale had the minimum error compared to seasonal scale. This result show decrease in ETO error in small time scales.

The city development is an unavoidable process which is due to different effects and ingredients and its result is the city development at different points and directions. To avoid results and problems resulted from city development, the city development and spread has to be done in a controlled way and based on scientific Principe and rules. Unscientific Cities growth have undesired effects and results as too much crowd in some areas of the city like, traffic increase, loss of resources and agricultural capacity around the city, damage to the environment, urban services and facilities reduction for some areas and etc. To reduce problems resulted from urban development and involve various factors in the development of the city as ecological factors such as geology and climate land use, slope, slope direction, height and etc an approach should be used which is able to interfere factors that are involved in urban development in urban development project based on their importance and regard natural development capacity and benefit from geographic information systems that are powerful tools. In this paper using ArcGIS for appropriate areas of development identification, prioritizing identified areas and hierarchical analyse for areas with development potential has been done. For this purpose, first, effective factors in skeletal urban development identified based on environment capacities and then effective factors converted to effective data in database in ArcGIS and next to choose the best area and prioritizing development areas, effective factors in urban development using hierarchical analyse (AHP) based on importance of effective factors are compared together and then using spatial analysis functions in ArcGIS appropriate areas for development determined based on priority.

Drought is one of the most important environmental events and also it’s the integral part of climate fluctuations. This phenomena is a specific condition of precipitation loss and high temperature that might happen in every climate condition. Drought condition awareness and drought intensities zoning might decrease risks of drought losses significantly. Present study is an attempt to evaluate accuracy of place interpolation methods for occurred drought intensities zoning in LARESTAN in 1387 using Percentage of normal precipitation Index (PNPI), standard precipitation index (SPI), deciles precipitation index (DPI), and Rainfall anomaly index (RAI). Therefore, it used data of 20pluviometry stations in LARESTAN that distributed appropriately and inverse distance weight (IDW) with 1 to 3 powers, ordinary kriging (OK), and universal kriging (UK) Methods, were studied.

Climate variability and change behavior of extreme events is important. To review some events, some climate indices for the detection surface by the Working Group on Climate Change and the World Meteorological Organization and climatology Committee research program on climate variability and predictability are introduced. In this paper, the changes in temperature and precipitation at the weather station 6 Bushehr Province during the period 1391-1371 using threshold values, and the nonparametric Mann-Kendall test for the presence of a linear trend has been used. The results show, Bushehr is highly exposed to the mean temperature, the frequency profile so reducing heating and cooling profiles. Cold nights and warm nights to other index increased thresholds of them have been impressive. Prolonged periods of increased summer heat in recent decades to a great show. DTR drop in the station area, tropical nights and warm nights increase in the length of the stations there. The research findings showed that: During the study period, a negative trend for the series of one-day maximum precipitation (Rx1day), maximum 5-day precipitation (Rx5day) and the simple daily intensity (SDII) can be seen in the province. The R10 index in research stations with positive trends. Check the index R20 and R25, shows that during the period studied, the research station has negative trends in the linear gradient. CDD index of consecutive dry days with precipitation have also increased in recent years coordinated. CWD index showed a decrease in rainfall in the region in recent years, coordinated by the number of consecutive wet days (CWD) is greatly reduced. Indexes Series R95 p and R99 p represent the province at the station volatility and decline in the latter years of the study period. Trends in Bushehr Province PRCPTOT index shows that the average rainfall in this region is low, thus decreasing trend is coupled with high volatility.

The purpose of this research is Landslide hazard regionalization using analytical hierarchy method and GIS technique. For this purpose affecting factors were binary compared using analytical method by indicating the weight of each factor as indicator for their effects in occurrence of landslide. Accordingly, the landslide regionalization hazard map was prepared to the use of weighed information layer and weighted coefficient of each factor. Results of this study show that the analytical hierarchy method is precise method for evaluation of landslide potential due to the use of binary comparison affecting factors and considering numerous factors for landslide evaluation at the same time in comparison to the other prevalent method and the results indicates that the percentage of high hazard class is 25 percent in AHP method.

The purpose of the present study was to identify the characteristics of temporal and spatial distribution of climatic phenomena are thunderstorms. Therefore, for the purpose of data on the frequency of thunderstorms in Tehran province with emphasis on temporal and spatial characteristics 7 state on thunderstorms were studied and analytically considered. The results showed the highest frequency of thunders toms in theyear2004 and the lowest frequency of occurrencewasin 2000; Mehrabad station and Chet garmostregions have had the lowest volatility during the period. Oscillating and linear trend and polynomial models when all stations except CHITGAR and geophysics has been an increasing trend. Maps of the spatial distribution and spatial patterns howled that Abali and Firoozkooh the higher stand lowest frequency geophysical thunder storms between stations in the period studied.

Hot and mineral springs are one the most beautiful attractions around the world and have a high contribution in tourism industry in some countries. In Iran more than 460 hot springs have been identified and it seems that there are many more to be explored. Different aspects of these springs such as spring rise, pools and water canals, deposits with different chemical compositions and colors, different algae coatings, historical monuments related to hot springs and natural landscapes around them are attracting many tourists. Another more important tourism attraction of hot springs is their therapeutic uses that have had a long history around the world and also in Iran. Hot springs therapeutic uses are deeply related to their water geochemical characteristics. Fortunately Iranian hot springs have vast geochemical variations. Although these springs have high tourism potentials, they have not been introduced appropriately nationally and internationally. They have not enough and appropriate health care and welfare facilities. Scientific introducing and studies of theses springs alongside with providing health care and welfare facilities can make Iran as one of the therapeutic and natural tourism poles in the world.

Recognition and grading land potential, can contribute to the optimal utilization of these resources is necessary. Also identify areas prone and its distribution in different regions, we can identify potential land management methods appropriate to apply the maximum benefit to not be done. In this study, soil and land, topography (slope, altitude), and meteorological data (average rainfall) data geology (rock type) and susceptibility to erosion in Mahshahr city were studied. For this purpose, layer by using available data, a database in GIS environment were prepared and analyzed. After preparation of layers, with integrated software environment ArcGis10.2 maps obtained using the hierarchical model, different regions based on their talent into three zones, good, fair or poor were zoning.